Post-September 11 surveillance provisions that, barring a last-minute deal in Congress, are set to expire at midnight Sunday:

Section 215 of the Patriot Act

This has been used to authorize the NSA's bulk collection of domestic telephone records, although an appeals court ruled the law could not fairly be read to support that program. The ruling was put on hold, pending the debate on Congress. Section 215 is used by the FBI 200 times a year to obtain business records, including hotel bills, travel vouchers and Internet data relevant to terrorism investigations. The FBI says that collection is useful, though a Justice Department report said the bureau could not point to any terrorism cases cracked because of the program, as of 2009. If the program lapses, the FBI will have to go back to pre-September 11 language that is much more restrictive.

Section 206 of the Patriot Act

This authorizes "roving wiretaps" in national security cases. Commonly used in drug cases, such wiretaps allow the FBI to target a suspect rather than a device. If this provision expires, the FBI would have to get a separate order for each communications device it wants to intercept.